The present invention concerns electrical switches of the type having a movable magnet which acts on a conductive armature to move the armature relative to one or more sets of electrodes. The armature may move into and out of shorting relation with spaced electrodes. Or the electrodes may form a potentiometer or some other arrangement providing a desired logic or output. Examples of this type of switch are found in U.S. Pat. No. 5,867,082, the disclosure of which is incorporated herein by reference.
The switches have a carrier sheet on which the electrodes are formed by screen printing, etching or other suitable process. The carrier sheet can be made of a variety of materials depending on the application. Polyester film, circuit boards and dielectric-coated thin steel sheets are possibilities. Rotary and slide switches typically include a knob mounted on the carrier sheet for rotary, linear or complex motion. The knob carries a magnet for movement therewith adjacent the external surface of the carrier. Electrodes are formed on the opposite side of the carrier. An armature is made of electrically conductive and magnetic material. By magnetic material it is meant that the material is affected by a magnet. The magnet holds the armature up against the underside of the carrier and, accordingly, against the electrodes. Movement of the knob drags the armature around on the electrodes. In the case of on-off switches, the magnet moves the armature into and out of shorting relation with the switch contacts. The armature can be a flat, disc-shaped element. Alternately, it can be two or more spherical balls. Further alternate armature configurations include a flipper having two or more stable positions wherein different sets of contacts are shorted. A detent gear can be used to provide tactile feedback of movement into and out of switch closure. Preferably some sort of substrate, ball retainer or blister pack is used to protect and seal the electrodes and armature. There may be a spacer with an opening in which the armature is disposed and which permits movement of the armature.